Delivery device on a sheet processing machine

ABSTRACT

The invention pertains to a delivery unit on a sheet-fed processing machine, preferably a sheet-fed printing or sheet-fed varnishing machine. The aim of the invention is to provide a delivery unit of this type such that permits in-line transport of printed and/or varnished sheets to at least one additional production line. To this end, the delivery unit  1  includes an endless revolving sheet conveyor system  5  that conveys the sheets to a first delivery stack  9  and a sheet withdrawal drum  7  that functions as a diverter for transferring sheets to a second stacking system. The sheet withdrawal drum is arranged upstream of this delivery stack relative to the conveying direction. A sheet transport system  20  is arranged downstream of the drum  7  and a folding module  12  is arranged downstream of the sheet transport system in the rotational direction  10  of the drum.

FIELD OF THE INVENTION

The invention pertains to a delivery unit for a sheet-fed processingmachine. The delivery unit is preferably applicable to sheet-fedprinting and/or sheet-fed varnishing machines.

BACKGROUND OF THE INVENTION

A type of delivery unit for rotary sheet-fed printing machines isdisclosed in DE 24 30 212 A1. This delivery unit contains a sortingdevice that selectively deposits the printed sheets on two deliverystacks as a function of a measurement related quality control carriedout within the printing machine. A revolving first chain conveyortransports the printed sheets to a first delivery stack. The first chainconveyor is associated with a withdrawal drum having gripper systems. Asecond chain conveyor is arranged downstream of the withdrawal drum. Theprinted sheets are deposited on the first or the second delivery stackdepending on the determined quality.

DE 198 19 491 C1 discloses a sheet delivery unit for a rotary printingmachine having an endless revolving conveyor system that transports thesheets to a first delivery stack. A drum that functions as a diverterand comprises at least one gripper system is arranged upstream of thedelivery stack. The drum is operable to selectively or continuouslywithdraw sheets and is assigned to the lower strand of the conveyorsystem. Another stacking system is situated adjacent to and assigned tothe drum for depositing sheets. A sheet guiding device with a recessthat extends over the format width is arranged outside the lower strand.The orbit of the drum's gripper system intersects the recess, and thesecond stacking system is arranged approximately underneath the drum.The second stacking system may be configured in the form of a pallet ora skeleton container, for example, for receiving waste sheets, as wellas in the form of a stacking system with stop elements and aligningdevices in order to produce exact stacks.

Another delivery unit for a rotary sheet-fed printing machine isdisclosed in DE 43 22 324 A1. This delivery unit has, among othercharacteristics, a modular design. For example, a dryer section isarranged within the delivery unit in the form of a module. The deliveryunit is also assigned a copy diverter that is modularly arrangeddownstream of the last chain wheel of the sheet conveyor system in theconveying direction. Waste sheets as well as test sheets can be stackedseparately outside the main stack by activating the gate.

DE 195 23 881 A1 discloses a rotary printing machine with a deliveryunit and revolving conveyor means. An additional processing unit withcylinders for guiding the sheets or products is arranged downstream ofthe delivery unit in the conveying direction. Folding processes can becarried out during transport of the sheets/products. For this purpose,at least one folding module is arranged downstream of the delivery unitin the conveying direction. One of the folding modules is integratedinto the transport path of the revolving conveyor means.

One disadvantage of the two latter-mentioned designs is that thesubassemblies arranged downstream of the sheet conveyor systems, e.g.,the copy diverter and the stack or the folding modules for additionalprocessing arranged downstream of the conveyor systems, inevitably leadto an increased length of the processing machine.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, an object of the present invention isdeveloping a delivery unit for a sheet-fed processing machine in whichthe aforementioned disadvantages are eliminated and in particular, anin-line transport of the printed and/or varnished sheets to at least oneadditional production line is possible.

A first advantage is obtained in that the printed and/or varnishedsheets can be selectively deposited on a first delivery stack or—whenactivating a drum that functions as a diverter—on a second deliverystack. Alternatively, the printed and/or varnished sheets can betransported to a folding module with at least one downstream foldingapparatus.

It is also advantageous if the second stacking system can be utilized asan auxiliary stacking device in a non-stop mode. When a stack exchangeneeds to be carried out on the first delivery stack, a sheet transportinterruption is produced by means of the drum that functions as adiverter in order to prevent a possible collision between the arrivingsheets and the non-stop device to be inserted. This operating modeimproves the process stability during depositing of the sheets on thefirst delivery stack. The production printing speed can be maintainedduring depositing of the sheets on the first delivery stack. Thedepositing of sheets with color variations as well as start-up sheets,etc., on the first delivery stack can be prevented by previously sortingout and depositing these sheets on the second delivery stack.

Another advantage is that the delivery unit can be universally utilizedif it is coupled to a folding module with at least one foldingapparatus. This means that an intermediate storage of the sheets is nolonger required and that commercial products of variable format can beproduced.

The folding apparatus(es) can be coupled to the delivery unit,particularly to a drum that sorts out the sheets, in the form of afolding module. It should be possible to laterally slide one suchfolding module into and out of the delivery unit in accordance with thedraw out-unit design.

The folding apparatuses are preferably configured in accordance with thebuckle fold principle; alternatively, it is also possible to configurethe folding apparatus in accordance with the knife fold principle or acombination of both principles. Since the material to be printed isalready present in the form of sheets, it is no longer necessary toutilize a cross cutter in the delivery unit.

It is also advantageous if the delivery unit can be utilized in anoperating mode that serves exclusively for the production of foldedsheets by utilizing a drum that functions as a diverter. In addition,the first delivery stack can be utilized for waste sheet or test sheetdelivery, for example, by briefly deactivating the drum. The deliveryunit can still be utilized for delivery of unfolded sheets to a firstdelivery stack while the drum is inactive.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of an illustrative delivery unit according to theinvention having a first and a second stacking system and a foldingmodule.

DETAILED DESCRIPTION OF THE INVENTION

A delivery unit 1 is arranged in a sheet-fed rotary processing machinedownstream of a printing unit or a varnishing unit in the conveyingdirection 2 of the sheets to be deposited. The delivery unit 1 consists,among other things, of an endless revolving sheet conveyor system 5 withseveral gripper systems fixed thereon. The sheet conveyor system 5 ispreferably configured as a chain conveyor with upper and lower strands3, 4. The sheet conveyor system 5 conveys printed and/or varnishedsheets to a first delivery stack 9 (main stacking system) and depositsthe sheets thereon.

A sheet guiding device 6 that preferably can be actuated pneumaticallyis assigned to and spaced apart by a short distance from the lowerstrand 4 of the sheet conveyor system 5. A recess that extends over theformat width is arranged in the sheet guiding device 6 outside the lowerstrand 4 and spaced apart from the sheet conveyor system 5 by a shortdistance. In the area of the recess, a drum 7 for guiding the sheets isassigned to and arranged underneath the lower strand 4. The outersurface of the drum 7 is provided with at least one gripper system, theorbit of which intersects the recess. A second stacking system 8 ispreferably arranged approximately underneath the drum 7 for thedepositing of sheets.

The sheet conveyor system 5 extends as far as a point above the firstdelivery stack 9 that functions as the main stack. Relative to theconveying direction 2, the drum 7 for guiding the sheets is assigned tothe sheet conveyor system 5 upstream of the first delivery stack 9.Dryer systems 21 (UV dryer, IR dryer or other systems) are preferablyarranged upstream of this drum 7 in the conveying direction 2. Inaddition, measuring devices for quality control of the sheets arearranged upstream of this drum 7, for example, on the lastprinting/varnishing unit.

Relative to a single format rubber blanket cylinder or plate cylinder,it is preferable to configure the drum 7 as a double format drum 7 withtwo gripper systems symmetrically arranged on the outer surface.However, it would also be possible to configure the drum 7 with a singleformat diameter and one gripper system or with a multiple formatdiameter and a corresponding number of gripper systems symmetricallydistributed over the circumference.

The drum 7 functions as a diverter for selectively or continuouslywithdrawing sheets from the flow of sheets being conveyed by the sheetconveyor system 5 that revolves in the direction of the first deliverystack 9. For this purpose, the drum 7 is preferably assigned to ahorizontally arranged section of the sheet conveyor system 5. Relativeto the rotational direction 10 of the drum 7, a sheet guide 11, which ispreferably coupled to a pneumatic system, is arranged in the sheetdelivery at a defined distance from the orbit of the gripper systems.

In a first variation, the sheet being guided on the drum 7 is depositedon the second stacking system 8. The second stacking system 8 may simplybe configured as a pallet or skeleton container for receiving wastesheets. Alternatively, stop elements and aligning devices may beprovided in order to exactly align the edges of the sheets forming astack.

In another variation, a folding module 12 is arranged downstream of thedrum 7 relative to the drum's rotational direction 10. In this respect,it is possible to slide the folding module 12 into and out of thedelivery unit 1 in accordance with the draw out-unit design.

Preferably, the folding module 12 slides laterally relative to theconveying direction 2 of the sheets. In one particularly preferredembodiment, it is possible to slide the folding module 12 into and outof the delivery unit 1 on its B-side. For this purpose, the foldingmodule 12 preferably can be displaced by means of linear guides or isprovided with lock-type rollers.

In a first operating mode, the second stacking system 8 remains in thedelivery unit 1 and serves to receive sheets that are not delivered tothe folding module 12 by the drum 7. These sheets can consist, forexample, of waste sheets produced during start-up of the processingmachine. The second stacking system 8 is then deactivated, and thesheets are delivered to the folding module 12 by the drum 7. In a secondoperating mode, the second stacking system 8 can be deactivated in thedelivery unit 1 or removed from the delivery unit 1 such that the sheetsare exclusively delivered to the folding module 12 by the drum 7. Whenthe second stacking system 8 is deactivated or removed, the firstdelivery stack 9 can be utilized for the depositing of sheets if, forexample, waste sheets are produced.

Relative to the rotational direction 10, sheet transport system 20, forexample, a conveyor belt system, is preferably arranged downstream ofthe drum 7. The folding module 12, which comprises at least one foldingapparatus 13, is arranged downstream of the sheet transport system 20.

The sheet transport system 20 can compare, for example, of a drivenconveyor belt system with an endless belt that forms an upper and alower strand and serves for friction-held sheet transport. In this case,the transport direction of the conveyor belt system is directed oppositeto the conveying direction 2 of the sheet conveyor system 5 situatedabove the conveyor belt system.

A guide element 22 is preferably arranged parallel to the axis of thedrum 7 in order to guide the sheets between the drum 7 and the sheettransport system 20, with this guide element promoting the process of“peeling” the sheet off the drum. At the same time, the guide element 22serves to guide the respective sheets released from the gripper systemof the drum 7 to the sheet transport system 20. The guide element 22 ispreferably provided with comb-shaped tines pointed in the direction ofthe outer surface of the drum 7. The guide element is arranged a shortdistance from the drum 7 such that the grippers of the drum 7 are ableto pass through the intermediate spaces between the tines of thestripping element 22. The cone-shaped tines transform into a guidesurface for guiding the sheets in the direction of the sheet transportsystem 20.

The front part of the guide element 22 is tapered in the direction ofthe drum 7, preferably in a wedge-shaped fashion, with the guide surfacefor guiding the sheets preferably being arranged adjacent to the taperin the direction of the sheet transport means 20. In this case, thecomb-shaped tines may also have in a tapered configuration system.

In another variation, the guide element 22 consists of a flow channelthat is arranged parallel to the axis of the drum 7 and coupled to apneumatic system, with the flow channel being configuration with tinescan that transform into the guide surface. The guide surface and/or thetines contain openings for discharging blasting air in order to promotethe process of “peeling” the sheets off the drum 7, as well as that oftransfer to the downstream sheet transport system 20.

In another variation, the drum 7 for guiding the sheets is coupled, forexample, to a pneumatic system via a rotary pneumatic connection in theaxial center. This provides the drum 7 with an air-permeable outersurface such that it can be operated as a drum 7 that carries the sheetson an air cushion. Alternatively, several nozzles that can be actuatedpneumatically and/or mechanical actuator (for example, lifters) can bearranged on the drum 7 in the area of the grippers in order to promotethe separation of the front edge of the respective sheet from the drum 7for the additional transport in the direction of the sheet transportsystem 20.

The folding module 12 contains at least one folding apparatus 13. Eachfolding apparatus 13 may be configured in accordance with the bucklefold principle, the knife fold principle or a combination thereof.

A folding apparatus 13 of this type contains an adjustable stop 15 thatpreferably can be adjusted to variable formats and is arrangedunderneath the sheet conveyor system 5 in the direction of an ascendingdelivery section 16. At least a first and a second folding roller 18,19, which preferably extend over the maximum format width of the sheetmaterial and can be driven in opposite directions, are arranged in abuckle-folding chamber 17.

If the folding module 12 contains only one folding apparatus 13, afolded sheet delivery or a folded sheet stacker is arranged downstreamof the folding rollers 18, 19 in order to laterally transport the sheetsout of the delivery unit 1 in the horizontal position or standingvertically on a fold.

If the folding module 12 contains several folding apparatuses 13, asecond, and if applicable, an additional folding apparatus 13 arearranged downstream of the first folding apparatus 13, wherein thefolded sheet delivery or the folded sheet stacker is arranged downstreamof the last folding apparatus 13.

An exemplary embodiment of the invention including a first foldingapparatus 13 that is configured in accordance with the buckle foldprinciple is described in greater detail below. Relative to therotational direction 10, the guide element 22 as well as the sheettransport system 20 are arranged downstream of the drum 7. At least twofolding rollers 18, 19 that extend over the maximum format width of thesheet material and can be driven in opposite directions are arrangeddownstream of the sheet transport system 20 in the buckle-foldingchamber 17. Relative to the transport direction of the sheet transportmeans 20, a folding pocket 14 is arranged downstream of the foldingrollers 18, 19. A stop 15 is arranged within the folding pocket 14 suchthat it can be variably positioned according to the sheet format. Afterthe first fold is produced, the sheets may, if so required, betransported to at least one additional folding apparatus 13. Forexample, a cross fold can be produced in the first folding apparatus 13and a longitudinal fold can be produced in the downstream second foldingapparatus 13, preferably in accordance with the knife fold principle. Athird folding apparatus 13 that is realized, for example, in accordancewith the knife fold principle is arranged downstream of the secondfolding apparatus 13. Another longitudinal fold is produced in the thirdfolding apparatus 13. The folded products thus produced can betransported out of the delivery unit 1 laterally to the conveyingdirection 2 in overlapping form or preferably standing on a fold.

The folding module 12 is coupled to the machine controller of thesheet-fed processing machine. In this case, pre-adjustment of themachine data also takes place synchronously in the folding module 12.For example, the folding module 12 is automatically adapted to differentformat sizes or thicknesses of the material to be printed, whereinpreviously stored data can be retrieved for processing repeat orders.

An exemplary mode of operation of the invention is described below:

The sheets conveyed by the sheet conveyor system 5 pass through thedryer system 21 (and, if so required, a powdering station) in theconveying direction 2 and are transported to and deposited on a firstdelivery stack 9. In this case, the gripper systems of the driven drum 7are inactive.

When the gripper systems of the drum 7 are selectively activated, thesheets can be transferred to the second stacking system 8 in therotational direction 10 of the drum 7. This operating mode can berealized, for example, when waste sheets or sheets of reduced qualityare produced, when test sheets are withdrawn, and when a non-stop stackexchange needs to be performed (first delivery stack).

Alternatively, the sheets can be continuously or periodicallytransported to the downstream folding module 12 in the rotationaldirection 10 of the drum 7. If a periodic transport takes place,unfolded sheets can be transported, if so required, to the firstdelivery stack 9 or, alternatively, to the second stacking system 8.

If the drum 7 and the folding module 12 are activated, the individualsheets being introduced into the folding pocket 14 come in contact withthe stop 15 that can be adjusted according to variable formats. Due tothe still existing kinetic energy, the sheets respectively form ahanging-down buckle fold in the buckle-folding chamber 17, with thebuckle folds being individually taken hold of by the folding rollers 18,19, so that the sheets are successively pulled through the gap betweenthe folding rollers 18, 19 and a first fold is produced in the sheet.The sheets provided with the first fold are transported, if so required,to downstream folding apparatuses 13 and subsequently delivered.

1-9. (canceled)
 10. A delivery unit for a sheet-fed processing machinecomprising: an endless sheet conveying system for conveying sheets to afirst delivery stack; a sheet removal drum that functions as a diverterupstream of the first delivery stack relative to the sheet conveyingdirection, the sheet removal drum including at least one gripper systemand being associated with a lower track of the sheet conveying system; asecond sheet stacking system associated with the sheet removal drum; asheet guiding device arranged in proximity to the lower track of thesheet conveying system for transferring sheets to the second sheetstacking system, the sheet guiding device including a recess thatextends over a predetermined format width; a sheet transport systemarranged downstream of the sheet removal drum in the direction ofrotation of the sheet removal drum; and a folding module including atleast one folding apparatus arranged downstream of the sheet transportsystem.
 11. The delivery unit according to claim 10 further including aguide element that is arranged parallel to a rotational axis of thesheet removal drum between the sheet removal drum and the sheettransport system.
 12. The sheet delivery unit according to claim 11wherein the guide element includes comb-shaped tines that extend in thedirection of an outer surface of the sheet removal drum and form a guidesurface.
 13. The sheet delivery unit according to claim 11 wherein afront part of the guide element is tapered in the direction of the sheetremoval drum.
 14. The sheet delivery unit according to claim 10 whereinthe folding apparatus is configured according to the buckle foldprinciple.
 15. The sheet delivery unit according to claim 10 wherein thefolding apparatus is configured according to the knife fold principle.16. The sheet delivery unit according to claim 10 wherein the foldingapparatus includes an adjustable stop arranged underneath the sheetconveying system in the direction of an ascending delivery section ofthe sheet conveying system and wherein at least two folding rollers aresupported in a buckle-folding chamber such that they can be driven inopposite directions.
 17. The sheet delivery unit according to claim 16wherein the stop is arranged in a folding pocket so as to be adjustableto different formats.
 18. The sheet delivery unit according to claim 16wherein the folding rollers extend over a maximum format width.
 19. Thesheet delivery unit according to claim 10 wherein the folding module isslidable laterally relative to the conveying direction of the sheetsinto and out of the delivery unit.